Printing telegraph system



Nov. 17, 1942 c. J; FITCH 2,302,017

PRINTING TELEGRAPH SYSTEM File May 8, 1941 L L L I v m FM F IG.1. r

7'2 2o E I Q o I Ft lT ras 27 E 17 5 Patented Nov. 17, 1942 OFFICPRINTING TELEGRAPH SYSTEM Clyde J. Fitch, Endwell, N. Y., assignor toInternational Business Machines Corporation, New York, N. Y., acorporation of New York Application May 8, 1941, Serial No. 392,408 6Claims. (c1. 17s 5s.1)

This invention relates to a printing telegraph system, and moreparticularly to such systems utilizing start-stop impulse distributingmeans.

The present invention constitutes a modification of the system describedin the copending application Serial No. 370,675, filed December 18,1940. I

I In the said copending application, provision is made for controllingthe operation of the impulse generating and distributing means by meansof a start-stop electronic oscillation generator; whereas, in thepresent application, the stepping operations of the distributing meansis under control of electromagnetic relay means. The said relay meansare energized, at periodic intervals, by means of an oscillatory controlcircuit including a pair of electric storage means, such as condensers,the discharging operations of which are under control of the relaymeans, which oscillatory circuit is effective to control, at periodictimes, the conductivity of an electron discharge path, the said pathbeing connected to the relay means for causing the energization of thelatter when ever the discharge path is rendered con I ductive.

Accordingly, an object of the present invention resides in the provisionof periodically operated electromagnetic relay means for controlling theoperations of impulse distributor actuating means, which relay means areunder the control of an oscillatory circuit.

Other objects of the invention will be pointed out in the followingdescription and claims and illustrated in the accompanying drawing,which discloses, by way of example, the principle of the invention andthe best mode, which has been contemplated, of applying that principle.

In the drawing:

Fig. l is a wiring diagram showing the circuit connections of thecontrol elements of a preferred type of signaling system. I

Fig. 2 shows the wave forms of the variably timed signals generated bythe system.

Referring now to the circuit diagram, the system to be described is ofthe start-stop type, wherein a continuous signal or current condition isimpressed upon the associated transmission medium at the times charactersignals are not impressed thereon.

The present description will be limited to means for initiating andtransmitting the .permutation signals, which incorporate the step bystep impulse distributing means and the associated start-stop controlmeans.

Suitable means for ters in accordance with the received signals are wellknown to those skilled in the art.

The impulse distributing means, generally in dicated by the referencecharacter D, comprises two stationary conducting ring assemblies in-'cluding the rotatable contacts 9 and I0, respec-- tively,which areadapted to engage and connect progressively the individual conductingsegments I I to the related common conducting segment I2.

The said contacts are rotated by a shaft indicated by the referencecharacter I3, having a ratchet I4 affixed thereto. The said contacts 9and I0,

shaft I3, and ratchet I4 are advanced step by step by the spring urgedpawls I5 pivotally supported by the individual pivoted armature arms I6of the control magnets MI and M2. Each step the contacts are advanced adistance equal to half the length of the longer conducting segments l I,such as segments P, and I6. The lengths of the remaining segments I I,such as O and S'are half that of the previously mentioned segments. Thesegments and contacts are so arranged that, when one of the contacts 9transfers, for example, from segments I to 3, or 3 to 5, one of the con-:;tacts I0 sweeps-across the central portions of ;segments,respectively.

One terminal of each of the magnets MI and M2 is connected to thepositive terminal I! of a suitable power supply. The other terminal ofmagnet MI is connected to the contact I2 ofrelayRZ, and the otherterminal of magnet M2 is connected to contact II of the said relay. Thearmature of relay R2 is connected to the negative terminal I8 of thesaid power supply. With the contacts conditioned as. shown in thecircuit "diagram, the magnet MIis connected to the said terminals of thepower supply by means of conditions, to efiect engagement of theassociated armature with the contacts II and I2, alternately. In-thismanner, it will be seen, that magnets MI and M2 are energizedalternately to advance,

step'by step, the contacts 9 and I'0, thereby making the individualcontrol circuits, associated: with the distributor D,availablesuccessively, dur-; receiving the signals and recording thecharac-t55'",'ing theoperationiof the distributor. The timed;

interval during which the distributor is operated will be referred to asa signaling cycle.

In addition to relay R2, relays RI and R3 are provided, the coils ofwhich are connected in series, and are connected in the output circuitof the electron discharge device TI. The purpose of the relays RI and R3will be understood presently.

The control circuits I9, or signaling channels, are connected to theindividual conducting segments II, namely, I6, and the normally opencontacts TCI--TC6, respectively. The said contacts TCITC6 representdiagrammatically the well known control contacts which are operatedpermutatively to control the initiation of the character signals, bysuitable means, such as the transmitting teleprinter devices shown in U.S.

Patents Nos. 1,214,515 and 2,161,564. Upon operation of any one contactor any combination of contacts of the group TCI--TC6, the normallyclosed contacts TC are opened. The latter are connected by conductor 20to the S conducting segment of the distributor. The contacts TCI, T03,and T05 are also connected by a common conductor 2| to the P segment ofthe distributor, and by means of contacts I4 of relay R3 to the cathodecircuit of electron discharge device T2, which is of the double triodetype, and the elements of which are connected as a well known type ofoscillator. The output circuit of the device T2 includes the primarywinding of transformer 22, the secondary winding of which can beconnected to any suitable transmission medium. The contacts T02, T04,and TCG are connected by a common conductor to contact I3 of relay R3.

Now, so long as the contacts TCI-T,C6 remain in the normal positionsshown, a circuit can be traced from the positive terminal I! of thepower supply to conductor 23, conducting segment 0, contacts II),conducting segment S, conductor 20, normally closed contacts TC,conductor 24, resistor 25 to the control grid of device TI, andcontinues through resistors 26, 21, and 28 and conductor 29 to thenegative terminal I8 of the said power supply. By means of the describedcircuit, the negative biasing potential, impressed upon the said controlgrid through resistors 26, 21 and 28 which are included in thegrid-cathode circuit of device TI, is overcome by the positive potentialimpressed thereon, thereby rendering the device conductive as long ascontacts TC remain closed.

The coils of the said relays RI, R2, and R3 are included in the outputcircuit of device TI, as mentioned before, and are energized, at thetimes the said device is conductive, to close the related contacts I2and I4 as shown, and to open the contacts I0, I2 and I3, respectively.The circuit, just referred to, can be traced from the positive terminalI! of the power supply to coil of relay R3, coil of relay R2, coil ofrelay RI, anode and cathode of device TI and conductor 30 to thenegative terminal of the said power supply. It is evident that theoperation of the said contacts III-I4 can be effected, by means ofsingle relay means instead of the three individual relays. It has beenfound, however, that, for the present purposes, the contact timingarrangement can be controlled to a greater degree by the use ofindividual relays as shown.

Another circuit can be traced from the positive terminal I! of the powersupply to conductor 3|, center tap connection of the primary winding ofthe device T2, conductor 32, armature and contact I4 of relay R3,conductor 2|, segment P of the uppermost conducting ring of thedistributor D, contacts 9, the related common conducting segment I2, andconductor 33 to the negative terminal I8 of the said power supply,thereby causing the device T2 to oscillate and impress the continuoussignal upon the secondary windmg of transformer 22 and the associatedtransmission network. This continuous signal conditron is indicated bythe character A in Fig. 2.

Now, so long as contacts TC remain closed, the mentioned circuits remainconditioned as described to permit (1) the continuous signal to beimpressed upon the secondary winding of transformer 22, (2) the controlgrid of device TI to be conditioned by a sufficient positive potentialto overcome the negative biasing potential impressed thereupon to renderthe device conductive, and relays RI to R3 energized, and (3) the magnetMI to be energized by a steady current flow therethrough to hold theratchet mechanism In the position shown in the circuit diagram.

However, upon operation of any one of the contacts TCI-TCI5, or anycombination thereof, contacts TC are opened, thereby removing thepositive potential from the said grid of device TI. The normal negativebiasing potential impressed on this grid through resistors 26, 27, and

"28 is effective now to render the device non-conductive, and conseuentl can 152, and R3 to be d energi zed. fip o r i d ezfir gi non ofrelay R3, the associated armature is transferred from contact It to I3to open the cathode circuit to device T2, thereby causing the latter tobe non-conductive. In the present type of system, the cessation of thecontinuous signal condition is termed the start signal, and is indicatedby the character B in Fig. 2.

Upon deenergization of relay R2, the associated armature is transferredfrom contact I2 to- II to effect energization of magnet M2, anddeenergization of magnet MI, thereby causing the distrlbutor contacts 9and IE! to be advanced one s ep.

Upon deenergization of relay RI, the associated armature engages contactIn to connect the nor- V mally charged condenser 35 to conductor 36 totransformer 22, anode and cathode elements of transfer the charge tocondenser 31. T

of the resistors 21 and 28 are chosen so 51 3 1:)? closure of contact Inthe following circuit is established: from one terminal of the condenser35 to contact I 0, conductor 36, variable resistor 21, condenser 37,conductors 38 and 29 to the other terminal of the said condenser. Thetime constant factor is regulated by the R and C values of the resistor21 and condenser 31, which in turn determines the frequency of theoscillatory opxenr'iiltionzhnow to be described.

en e condenser 37 is full ch means of the described circuit, th neg a tis p tential mpressed upon the grid of device TI is neutralized by thepositive potential impressed thereupon by the fully charged condenser 31thereby causing the device TI to become conduc t1ve again and cause therelays RI, R2 and R3 to be energized. Energization of relay R2 causesthe distributor contacts 9 and I0 to be advanced another step, andenergization of relay RI causes tne condenser 35 to be disconnected fromcondenser 37. The latter now discharges through resistors 21 and 28,which discharge is regulated by the time constant of the dischargecircuit Upon discharge of condenser 31, the grid of de vice TI again isinfluenced by the negative potential impressed thereon to render thedevice non-conductive, thereby causing the relays R! to R3 to bedeenergized again.

In this manner, the described circuits are conditioned in an oscillatorymanner, at a frequency determined by the capacity of condenser 31 andresistance of resistor 23, until the circuit from the grid of device TIto the S and O conducting segments of the distributor is closed toimpress the steady positive potential upon the grid through resistor 25as described herein'above. That is, the said oscillatory conditionscontinue until the contacts 9 and [0 are returned to the normal homepositions shown in Fig. 1, when it is assumed the contacts TC are closedto permit thecircuit, just referred to, to be established.

Thus, it is seen, that oscillatory conditions are created to render thedevice conductive and nonconductive at equal, periodic intervals toeffect energization and deenergization of the relays Rl to R3accordingly. Relay RI controls the operation of the oscillating circuit,relay R2 controls the alternate energization of the magnets MI and M2,and consequently the step by step operation of the distributor, andrelay R3 controls the alternate connection of the TCI, TC3, T05 and TCZ,TC4, and TCB groups of control switches to the oscillation generator T2.During the described cycle of operation, the contacts 9 and I5 areadvanced eight steps before returned to the normal home position.

In order to describe briefly how the various signaling channels orcircuits are energized, or rendered conductive, as they are madeavailable, assume that when the said contacts TC are opened thatcontacts TCI, TC4, and T05 are closed. Now, during the first step, thestart signal (see B in Fig. 2) is initiated as described. During thesecond step, the contact [4 is closed, and since contacts TCI areclosed, a circuit can be traced as follows: from terminal I! toconductor 3!, device T2, conductor 32, contact [4, conductor 2!,contacts TCI, the I segment ll of distributor D, contacts 9, commonsegment l2, conductor 33 to terminal 18, thus rendering device T2conductive to generate the first character signal of the combination asindicated at C in Fig. 2. During the said second step, contacts I!)engage the 2 segment, but no circuit can be completed therethrough sincecontacts T02 are open; and assuming for the moment that the latter areclosed, no circuit could be established at this time, due to the factthat the contact 13 is open.

During the third and fourth steps, no signals are generated as indicatedat D and E in Fig. 2. During the fifth step, the device T3 is renderedconductive since contacts TC4 are closed and contact I3 is closed atthis time to generate the second signal of the combination as indicatedat F in Fig. 2. During the sixth step the third signal indicated at G inFig. 2 is generated, since contacts T05 are closed and contact I4 isclosed at this time. During the seventh step, the device T2 isnon-conductive, and during the eighth step, the said device T2 isrendered conductive continuously to generate the continuous signalindicated A in Fig. 2. It is remembered that this condition isestablished by the closed contacts TC and the circuits establishedthrough the P segment and the O and S segments. The oscillatoryconditions described are interrupted by these circuits, and are resumedonly upon the opening of the said TC' contacts to prevent the impressionof the steady positive potential upon the control grid of device Tl.From this detailed description, it is evident how various other signalcombinations can be initiated under control of the contacts TCI-TC6, andthe described impulse distributing means,

While there has been shown and described and pointed out the fundamentalnovel features of the invention as applied to a single modification, itwill be understood that various omissions and substitutions and changesin the form and details of the device illustrated and in its operationmay be made by those skilled in the art, without departing from thespirit of the invention. It is the intention, therefore, to be limitedonly as indicated by the scope of the following claims.

What is claimed is:

1., A system of the character described having impulse distributingmeans and actuating means therefor, the latter including a pair ofelectromagnets, control means including electromagnetic relay means foreffecting, at periodic intervals, the alternate energization of the saidelectromagnets, and means for controlling, at periodic intervals, theenergization of the said electromagnetic relay means.

2. A system of the character described having impulse distributing meansand actuating means therefor, means including electromagnetic relaymeans for effecting periodic energization of the said actuating means,and means including oscillatory control means for controlling, atperiodic intervals, the operations of the said relay means.

3. The invention set forth in claim 2 wherein the said oscillatorycontrol means comprises an electron discharge path and a plurality ofelectric storage means for controlling the conductivity of the saiddischarge path.

4. The invention set forth in claim 2 wherein the said oscillatorycontrol means comprises an electron discharge path and a plurality ofelectric storage means for controlling the conductivity of the saiddischarge path, and means controlled by the said relay means forcontrolling the operations of the said electric discharge means.

5. A system of the character described having impulse distributing meansand actuating means therefor, electron discharge means having an inputand output circuit, relay means connected in the said output circuit, anoscillatory control circuit connected to said input circuit forcontrolling, at periodic intervals, the conductivity of the saiddischarge means, means whereby the said relay means energized during theintervals the discharge means are rendered conductive, and meanscontrolled by the relay means for energizing, at periodic intervals, thesaid actuating means of the impulse distributmg means.

6. The invention set forth in claim 5, wherein the oscillatory controlcircuit includes capacitance means for controlling the conductivity ofthe discharge means, and means controlled by said relay means foreffecting the discharging operations of the said capacitance means.

CLYDE J. FITCH.

